Updated to match up to Paperclip 2.1.2

lib/dm-paperclip.rb

@@ -35,7 +35,7 @@
 require File.join(File.dirname(__FILE__), 'dm-paperclip', 'attachment')
 
 module Paperclip
-  VERSION = "2.1.0"
+  VERSION = "2.1.2"
   class << self
     # Provides configurability to Paperclip. There are a number of options available, such as:
     # * whiny_thumbnails: Will raise an error if Paperclip cannot process thumbnails of 

lib/dm-paperclip/attachment.rb

@@ -153,6 +153,22 @@ def self.interpolations
       }
     end
 
+    # This method really shouldn't be called that often. It's expected use is in the
+    # paperclip:refresh rake task and that's it. It will regenerate all thumbnails
+    # forcefully, by reobtaining the original file and going through the post-process
+    # again.
+    def reprocess!
+      new_original = Tempfile.new("paperclip-reprocess")
+      old_original = to_file(:original)
+      new_original.write( old_original.read )
+      new_original.rewind
+
+      @queued_for_write = { :original => new_original }
+      post_process
+
+      old_original.close if old_original.respond_to?(:close)
+    end
+
     def self.underscore(camel_cased_word)
       camel_cased_word.to_s.gsub(/::/, '/').
       gsub(/([A-Z]+)([A-Z][a-z])/,'\1_\2').

tasks/paperclip_tasks.rake

@@ -6,8 +6,8 @@ end
 
 def obtain_attachments
   name = ENV['ATTACHMENT'] || ENV['attachment']
-  raise "Class #{@klass.name} has no attachments specified" unless @klass.respond_to?(:attachment_names)
-  if !name.blank? && @klass.attachment_names.include?(name)
+  raise "Class #{@klass.name} has no attachments specified" unless @klass.respond_to?(:attachment_definitions)
+  if !name.blank? && @klass.attachment_definitions.keys.include?(name)
     [ name ]
   else
     @klass.attachment_definitions.keys
@@ -19,12 +19,13 @@ namespace :paperclip do
   task :refresh => :environment do
     klass     = obtain_class
     names     = obtain_attachments
-
+    instances = klass.all
+
     puts "Regenerating thumbnails for #{instances.length} instances of #{klass.name}:"
-    klass.all.each do |instance|
+    instances.each do |instance|
       names.each do |name|
         result = if instance.send("#{ name }?")
-          instance.send(name).send("post_process")
+          instance.send(name).reprocess!
           instance.send(name).save
         else
           true

test/test_integration.rb

@@ -18,6 +18,38 @@ class IntegrationTest < Test::Unit::TestCase
     end
   end
 
+  context "An attachment" do
+    setup do
+      rebuild_model :styles => { :thumb => "50x50#" }
+      @dummy = Dummy.new
+      @dummy.id = 1
+      @file = File.new(File.join(File.dirname(__FILE__),
+                                 "fixtures",
+                                 "5k.png"))
+      @dummy.avatar = @file
+      assert @dummy.save
+    end
+
+    should "create its thumbnails properly" do
+      assert_match /\b50x50\b/, `identify '#{@dummy.avatar.path(:thumb)}'`
+    end
+
+    context "redefining its attachment styles" do
+      setup do
+        Dummy.class_eval do
+          has_attached_file :avatar, :styles => { :thumb => "150x25#" }
+        end
+        @d2 = Dummy[@dummy.id]
+        @d2.avatar.reprocess!
+        @d2.save
+      end
+
+      should "create its thumbnails properly" do
+        assert_match /\b150x25\b/, `identify '#{@dummy.avatar.path(:thumb)}'`
+      end
+    end
+  end
+
   context "A model with no attachment validation" do
     setup do
       rebuild_model :styles => { :large => "300x300>",